I have a friend who wants to patent a really good idea. I've been doing some research, and I came across LegalZoom.com . The problem I'm having is whether to go all the way with a Design Patent or just keep with a provisional.

The patent is clothing related. It's not so much the design of the clothing item that is unique but how it functions. This is where it gets a bit lost because I'm not sure if the legal world would see it the way I do. From what I understand, Design patents protect the unique appearance, but not the functionality. Something tells me Murphy's law will come to bite me in the rear if I choose wrong.

Would it be a safe (and low cost) bet to go a provisional patent, until I figure out what the proper method would be? Legal zoom has one for $310 (after gov't filing fees) vs. the design patent which is over $1,100